Electric-arc lamp.



No. 746,830. PATENTED DEC. 15, 1903.

' T. HAMILTON-ADAMS. ELECTRIC ARC LAMP.

'APPLIGATION FILED JUNE 4, 1903.

N0 MODEL.

UNITED STATES Patented December 15, 1903.

THOMAS HAMILTON-ADAMS, OF LONDON, ENGLAND.

ELEOTRlC-ARC LAMP.

SPECIFIGATION forming part of Letters Patent No. 746,830, dated December15, 1903.

Application filed June 4, 1903. Serial No. 160,092. (No model.)

To all whzmt it may concern:

Be it known that I, THOMAS HAMILTON- ADAMS, asubjectofthe King of GreatBritain, residing at Howard House, Arundel street, Strand, London,England, have invented new and useful Improvements in Electric-ArcLamps, of which the following is a specification.

This invention relates to improvements in electric-arc lamps of the kindwherein the movable carbon is moved toward the fixed carbon bygravityand is raised by a solenoid-core which automatically grips the movablecarbon holder or carbon. In connection with lamps of this description ithas already been proposed to make use of a solenoid-core consisting oftwo clutch-pieces pivoted together, and which are magnetized under theinfluence of the solenoid, so that the two pivoted parts are caused torepel one another at one end, and'thus to grip the carbon orcarbon-holder at the other end. Furthermore, it has also been proposedto make use of a kind of toggle-clutch device in connection with a pairof magnets, the said toggle device being arranged inside thecarbon-holder in such a manner that when attracted by the magnets thetoggle-clutch expands and grips the carbon-holder, so as to raise thelatter with it asit moves under the attraction of the magnets. Now withall arrangements of this kind it is found in practice that the clutchesdo not possess sufficient power to properly control the carbons, and itis the object of this in vention to overcome this defect.

According to my invention I make use of a clutch device for gripping thecarbon or carbon-holder comprising, preferably, two parts, between whichthe carbon or carbon holder isheld, and one or both of which parts formsor form the core of a solenoid designed to raise the clutch, and therebythe movable carbon, when current is passed through it. To give thenecessary lateral movement to the clutch parts, I provide the solenoidwith one or more magnetpoles (which may be independent of the solenoid)so arranged as to provide the necessary conjoint lateral and axialattraction to cause the clutch to operate to grip and raise the carbon.

In the accompanying drawings, Figure 1 is an elevation of the chiefparts of an arc-lamp j at about its middle point.

having the improvements applied to it. Figs. 2 and 3 are two elevations,respectively at right angles to one another, of one form ofcarbon-clutch. Figs. 4 and 5 are a side elevation and a plan,respectively, ofa modified form of clutch; and Fig. 6 isa diagrammaticview illustrating the mode of action of the clutch device.

a is the upper or movable carbon, and b the lower carbon of the lamp, 0being the solenoid which is designed to control the are between the twocarbons.

(Z is a brass or like tube which is inserted in the solenoid c, and e isthe core of the said solenoid, this core also serving as the clutch forraising the upper or movable carbon a.

In the drawings I have illustrated two suitable forms of clutch-namely,that illustrated in Figs. 2 and 3 and that illustrated in Figs. 4 and 5.In the former arrangement the clutch comprises the two platesfand g,which are pivoted together at h at their lower ends and which arecurved, so as to conform to the cylindrical shape of the carbon. ,Whenthe upper ends of the two platesfand g are pulled apart into theposition shown, their lower ends grip the carbon. In the arrangementillustrated in Figs. 4. and 5 the clutch comprises the two curved plates2' and j, the former of which is provided with two rings or loops i 2",one at the top and one at the bottom thereof, and the latter with a ringor loop The carbon is passed through these three rings in the mannerillustrated in Fig. 4, so that by moving the two plates apart from oneanother they grip the carbon, the ring being of such a size that whenthe plates are approached toward one another the carbon is free to move.It will be clear that only one of the plates need be of magneticmaterial.

To provide the necessary lateral pull upon the clutch parts to effectthe gripping of the carbon, as above described, I provide the solenoidwith auxiliary poles, these being advantageously obtained by insertingat each end of the solenoid an iron ring 7c, whereby when current iscaused to How throuhg the solenoid c the necessary poles are provided.

The operation of the device will be clearly understood by reference tothe diagrammatic view shown in Fig. 6. When currentis caused to flowthrough the solenoid 6, it produces, for instance, the sets of polesmarked and in this figurethat is to say, the upper ring 70 will have anorth pole at the top and a south pole at the bottom, the clutch-core eand the bottom ring 70 being also similarly magnetized. It will thus beclear that the tendency is to draw the clutch-core upward into the saidsolenoid in the usual manner and also to pull apart the two portions ofthe clutch, and thereby lock the carbon, this result being due to thefact that the adjacent ends of the internal rings 70 7c and of theclutch-core are of such polarity relatively with one another as toproduce this effect.

In the case of differential lamps for series working an additionalshunt-coil Z is provided inside the solenoid-coil e, the said coil Zbeing antagonistic to the coil 6.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is 1. In electric-arc lamps, the combination with themovable carbon, of a solenoid, of

auxiliary poles in the solenoid and of a so lenoid-core composed of aplurality of parts which engage the carbon so as to grip the same whenthe solenoid is energized, substantially as hereinbefore described.

2. In electric-arc lamps, the combination with the movable carbon, of asolenoid, of auxiliary poles in the solenoid and of a solenoid-coreconsisting of a plurality of plates inclosing the carbon and pivotedtogether near their lower ends so as to grip the carbon when thesolenoid is energized, substantially as hereinbefore described.

3. In electric-arc lamps, the combination with the movable carbon, of asolenoid, of auxiliary poles in the solenoid and of a solenoid-coreconsisting of a plurality of plates having rings through which thecarbon passes and which grip the said carbon when the solenoid isenergized, substantially as hereinbefore described.

THOMAS HAMILTON-ADAMS.

Witnesses:

O. G. REDFERN, A. ALBUTT.

